I have a Bourne-Again shell script text executable named engine.bin that I want to install.
If I install the executable manually ./engine.bin I get a screen with the EULA I have to accept (by pushing space), then accept it by writing yes and then enter the installation path by typing /usr/local/engine.
Now I want to do the installation automatically through provisioning scripts without manual interaction. Is there a way to do this? I do not know if the installer accepts any parameters, unfortunately the thing is undocumented.
Based on the suggestion of bill-agee and jgr208 I wrote the following which is working for me:
#!/usr/bin/expect -f
set timeout -1
spawn /tmp/engine.bin
expect {
-gl "*Press SPACE or PAGE DOWN key to continue, U or PAGE UP key to scroll back*" { send -- " "; exp_continue }
-gl "*yes/no*"
}
send -- "yes\r"
expect -gl "*press ENTER to accept the default*"
send -- "/tmp/tce\r"
expect eof
If the executable allows you to spam input at it without waiting for each separate prompt to appear, you might be able to accomplish this with bash.
For example, this script will run program_that_takes_several_lines_of_input.py and send it four lines of input - three with text and one blank line:
#!/bin/bash -eux
./program_that_takes_several_lines_of_input.py <<EOD
first line
one enter keypress later
yet another line of input after the empty line above
EOD
If you need to stop and wait for each prompt to appear, the cram Python package may be a good fit for this scenario - I find it useful for tasks like this where you only need to send a few lines of input, but each line of input is different.
See:
https://bitheap.org/cram/
https://pypi.python.org/pypi/cram
Expect would also work, but I find that I reach working solutions a bit faster when using cram than with Expect.
pexpect is a great choice as well! See:
https://pexpect.readthedocs.org/en/stable/
Related
I wrote a script for resizing windows, which require orientation and value in form of fraction, like so:
resize.sh -h 1/2
and it works as expected.
I also added -k flag, which means that script require user input, like so:
resize.sh -k -h
and in the script:
read -rsn 2 fraction
which I parse to get values for numerator and denominator.
This works great from command line, but idea behind this is to bind resize.sh -k -h to some key combination, and pass following two keys as input. But when I run script from keyboard, it run as a background process which is not associated with any tty, so read could not get its input. Is there any way to redirect global input to background process, after running it from keyboard.
What I tried so far:
Redirection to /proc/$$/fd/0, which didn't work.
Redirectiong currently active tty stdin to read, like so:
read -rsn 2 fraction < /dev/pts/0
which actually worked, but problem is that not all windows are terminal, e.g. web browser.
If my question is unclear, please feel free to ask for additional clarifications or details, and thanks in advance :)
You can use a named pipe for the process communication.
I made am example script where the background proces is a function.
#!/bin/bash
pipe_name=/tmp/mypipe$$
mkfifo "${pipe_name}"
resize()
{
read fraction < "${pipe_name}"
echo "Resize window to fraction=${fraction}"
}
resize &
read -p "Enter your fraction: "
echo "${REPLY}" > "${pipe_name}"
rm "${pipe_name}"
thank you both for providing very useful information. The solution is combination of both, actually.
First I modified read command in resize.sh to get input from named pipe, as Walter suggested, than I wrote a new, kinda "wrapper" script, which executes resize.sh in background, and than, since Barmar pointed I need a gui window, it starts very small terminal window running read and passing input to named pipe. Further more, using wmctrl I manage to place small terminal window right where currently active window begins, and hide it below (thanks to openbox per-application properties), so it's technically not visible at all :)
It's really too hacky for my liking, but it was really the only option I could think of at this moment, so until I find the better way, this gets the job done.
Once again, thank you both for directing me toward solution, I really appreciate it, cheers :)
I'm working on a shell script, which has lot of network calls and installations. When it is executed I need to enter yes/no for each prompt. Which is fine.
But now i have a requirement to run it as cron. In which case i won't be able to give inputs for each of the prompt that comes up.
Is there any way I can automate this or have some mechanism of knowing in script that a prompt has come up?
Use the yes command to answer interactive prompts,
yes Y | ./script.sh
The above syntax constantly puts the string Y to all your prompts. You can pass the string as you need after yes.
You can also use expect tool meant for this, but you need to know the exact prompt message for capturing and responding to it accordingly. If your prompt is simple and just need a simple input to pass yes would be the right tool.
Also you can use bash built-in printf, but you need to add the responses manually depending upon the number of prompts you have to respond to, e.g.
printf 'Y\nY\nY\n' | ./script.sh
to send response as Y for three prompts. As again, to avoid doing this manually, prefer using the yes command.
I have to connect to a linux server from my own Ubuntu machine and operate directly on the server.
A dozen of folder names are listed in a LIST file. How to write sth. (like a bash script?) to carry out the following procedures?
for fold_name in LIST {
/******on my own Ubuntu*******/
-- open 2 new tabs of prompt terminal
-- run an ssh command in both
-- then input passwd and log in automatically in both
/******on the linux server*******/
-- cd to directory xxx/fold_name in both
-- run aaa.exe in 1st tab
-- vim sth in the 2nd tab
}
Once the loop of open-tab-login is solved, I guess the second part is routine as simple bash script except that I don't know how to specify between 2 tabs, either.
The point is I want all tabs in the same terminal. To this end, manually, I often Ctrl+Alt+T to create a prompt and Ctrl+Shift+T to open many tabs within it. And ssh...cd...... in each one. You see how annoying and cumbersome it is!
There are a few things you might like to research, which will get you a little closer.
You can run an ssh without a password, if you use an ssh key. Check out ssh-keygen, and the -i option in ssh.
Opening up tabs in gnome-terminal can be done via the method described here: Open a new tab in gnome-terminal using command line
You can run specific commands (e.g. aaa.exe) on a remote box over ssh, by including the command after the ssh: ssh user#remotehost aaa.exe.
If you want multiple commands, try enclosing them in quotes: ssh user#remotehost "cd /xxx; aaa.exe". Vim does not need to be in the directory in question in most cases: ssh user#remotehost vim /xxx/filename"
If you want to do something interactive (like vim), include the -t flag in ssh.
The tabs will be independent of each other - I'd probably run half of the command in one window, the other (e.g. runnning aaa.exe in one window, using one command, and the vim in another window, using another command, that I just happen to run at the same time. This way I can resize the windows, and arrange them relative to each other, and see both at once.
-- open 2 new tabs of prompt terminal
This depends on which desktop you're using. For gnome, gnome-terminal takes the -e option to specify the script to execute in the new terminal window. So, for something like this, you would execute gnome-terminal -e $script &, placing each instance of gnome-terminal in the background.
If you're using a different desktop, other terminal applications typically have a similar option. So, you'd point the terminal application to a script that's going to run in the terminal, and complete the rest of your task for you.
-- run an ssh command in both
-- then input passwd and log in automatically in both
This is going to be more complicated. The classical solution is the expect utility. There might be other similar tools that do similar things, but expect is pretty much the usual way these kinds of things have been done in the past. When it comes to trying to automate an interactive application, expect is really the only way to go. Unfortunately, expect uses a somewhat arkane syntax, that first-time users typically find confusing, and hard to understand. I grumble, every time I see no other alternative but to use expect to automate something, but this is pretty much the only option that's usually available.
I have a BASH script that runs on bg and print messages to the user when according to system events.
My problem is that after the echo of these messages, the user need to press on the ENTER key in order to get back to the prompt line.
Adding new line to the printed messages didn't help since it still comes from the bg and not from the user shell.
Does anyone have an elegant & simple solution to get the user back to the prompt line?
I will appreciate any help here..
You don't need to press enter to get to a prompt. You are still at the prompt that was there before the output was printed. Try just entering a command and hitting enter. (You can also hit ctrl-l to clear the screen instead of hitting enter to input an empty command.)
The problem here is that the background/alternative process has no relationship to the running shell session and so it is simply writing output to wherever the terminal sticks it. The process might be able to use control sequences to control the output location (but I don't know if this actually works).
Other than that there isn't much to be done about this that I'm aware of. And it isn't a problem in any real way.
We have a shell script that expects multiple user inputs to be entered when prompted. e.g
At first it may ask for the operation to be performed. When that answer is given, it may ask for username then password etc. We want to automate this task by providing the inputs using file redirection i.e.
script < input.
The input file will have all the answers for different questions that the script may ask. However it is not working and the shell script is reading only the first line of the input file. What do I need to change or use to make this work?
What you can use is the program expect. You create a script for it that tells it when to give what input to some command it executes. This way you can automate exactly the kind of thing you're struggling with.
More info on Google and here:
http://www.linuxjournal.com/article/3065
man page: http://linux.die.net/man/1/expect
You say 'it only reads the first line of input.'
So you have to kill the script?
Is there any output? (error messages especially)?
Are you redirecting STDERR to /dev/null or else where? If so, remove that.
Here is the hightest probability helper ... Modify the top-level script and add set -vx at the 2nd line. Then you'll be able to see what was processed, where it has stopped and possibly formulate theories about why it is not processing data.
Any chance that the input file was created in a Windows environment and the cr\lf pair is messing up the expected input?
I hope this helps.
Thanks all for commenting and answering. I tried except and that did not work. So I am going to mention what worked for us. Here was our workflow - 1. At the linux prompt, type the command, it was connect() in our case. 2. Once that command is given, the script would ask for parameters for the command like port number, server etc. we had to provide that manually 3. Then we again are presented with a shell prompt with another input. In our case, we were able to provide the first command connect() at the prompt using file redirection, but the parameter passing was an issue. The solution we found was provide the parameters inside the parentheses of connect only i.e. our input file for redirection would contain - connect(). This worked for us.